1. Field of the invention
This invention relates to water cooled exhaust systems and more particularly relates to a water-jacketed exhaust flange for reducing the exposed area between the exhaust outlet of a turbo charger turbine and the water-jacketed exhaust pipe members.
2. Prior Art
It is well-known that the temperature of the exhaust gas discharged from the exhaust gas outlet of a conventional internal combustion engine turbo charger unit is extremely high, sometimes in the range of 800-1200 degrees Fahrenheit. For this reason, it has become commonplace to surround the exhaust tubing downstream of the turbo charger exhaust gas outlet with a water circulating jacket assembly for transferring heat from the exhaust tube. Typically, the outside surface temperature of the water-jacketed exhaust pipe is on the order of only about 10 degrees Fahrenheit warmer than the ambient inlet water temperature used for cooling within the water-jacket. Such a substantial decrease in the exposed temperature of the exhaust conduit reduces the ambient temperature in the vicinity of the internal combustion engine (e.g.: in the engine room of a marine vessel). More importantly, such a reduced temperature exhaust conduit will not cause injury in the event of accidental contact with the skin.
Another means for reducing the exposed temperature of exhaust conduit is by blanketing same with a low heat transfer coefficient material, such as fiberglass covered with a flexible reflective material. Although such material would generally result in a reduction in the exposed temperature commensurate to the above-referenced water-jacketing, such blanketing material has the substantial tendency to become saturated with engine oil, diesel fuel and other liquids thereby becoming a serious fire hazard by virtue of being soaked with flammable materials and exposed to extremely high temperatures.
Although water-jacketed and thus cooled exhaust conduit systems have largely replaced such "dry" or blanketed systems, on such water cooled exhaust systems the area between the exhaust outlet of the turbo charger turbine and the beginning of the jacketed portion of exhaust conduit represents a serious safety hazard due to its temperature being on the order of magnitude of the exhaust gas temperature which, as mentioned above, can range between 800 and 1200 degrees Fahrenheit. The incidence of serious injury resulting from accidental contact with this relatively small area is alarmingly high. It is therefore highly desirable to eliminate this source of health hazard as well as to eliminate the source of unnecessary heat by means of a relatively simple and inexpensive article which can be built into the overall engine/exhaust system.